Means for molding backings for artificial teeth



Aug. 21, 1923. 3,465,473

. T. c. HANSEN MEANS FOR MOLDING BACKINGS FOR ARTIFICIAL TEETH Filed July 12, 1922 H p I Jwumwm Te @J EANSEN.

(5M Y M 6 mm m Patented Aug. 21, 1923.

PATENT @FlF-EQE.

THOMAS C. HANSEN, OF (FANEY, KANSAS.

Application filed July 12, 1922. Serial N0. 574,465.

1 My invention relates to means for-molding backings-for artificial teeth, and has for its object the provision of a celluloid or other hydrocarbon plate to be used as a pattern in molding the backing.

Another object of the invention is the use of such a hydrocarbon plate in connection with the formation of a solid bridge in dental work.

Other objects and advantages of the in- 2 vention will be apparent from the following description when taken in connection with the accompanying drawing, in which:

Fi ure 1 is a perspective view of the prepare roots of two adjacent teeth.

Figure 2 is a sectional View of a tooth with a crown pattern thereon.

Figure 3 is a perspective view of such crown patterns.

Figure 4 is a perspective view of the completed pattern for bridge work. Figure 5 is a similar perspective view looking from a different angle.

Figure 6 is a horizontal section taken on line 6-6, Figure 5.

Figure 7 1s a section through a mold, showing the bridge pattern.

. Figure 8 is a perspective view of the completed bridge, and

Figure 9 is a horizontal section taken through a modified pattern.

Referrin to the drawing more in detail, the numera 1 designates the prepared roots to be crowned and between which a bridge is to be supported. To each of these roots is fitted a hydrocarbon form 2 such as'described in my co-pending application Serial No. 550,154:. As set forth in said applica tion, ,a 36-gauge, 24-carat band 3 is fitted over the prepared root in order to get a proper adaptation therefor without causing irritation to the gums, and the form 2 is connected with the band 3 by casting wax 4. The form 2 is lined with casting wax 5 on its interior, and may have wax applied to the exterior thereof at indicated by numeral 6.

The backing for the porcelain tooth 7 is cast integral with the crowns and the mold is made by the use of a hydrocarbon or celluloid plate or form 7 which is provided with a dovetail rib 8 on one face thereof.

After the crown patterns are prepared as above described the backing form 7 is placed between the crown forms and united thereto by casting wax 9, as indicated in Figures 5 and 6. Casting Wax may be added, of course, at any points desired in order to reinforce thebacking and bring the same to the exact shape desired. The completed pattern is then placed in a mold 10 by means of pin 11, and the mold heated to volatilize the casting wax and hydrocarbon forms. After the pattern is volatilized the gold or other casting material is then poured into the mold and the entire bridge, including the two crowns and backing, is cast in one piece, as indicated by numeral 12 in Figure 8.

In the modified form of the invention shown in Figure 9 the numerals 1, 2, 5 and 9 represent the same elements shown in Fi ures 1 to 8, inclusive, but instead of the 05- luloid plate 7 I have used a celluloid plate 13 provided with the tubular portions 14. This pattern is placed in the mold in the manner previously described and the finished bridge will be provided with two apertures for receiving the pins of the facing which will be cemented to the backing.

rom the foregoing description it will be seen that I have provided a novel article points desired, as

- and method for casting bridge work in one piece which presents an advantage over the soldering method, in that shrinkage and expansion are eliminated. Furthermore, there is a great saving in time in assemblin and finishing the backing and crowns. It s ould also be noted that this bridge may be cast hollow, if desired, and filled on the lingual surface with synthetic porcelain, cast porcelain or any other material to save gold.

- In accordance with the patent statutes, I have described what 1 now believe to be the best embodiment of the invention, but I do not wish to be understood thereby 'aslimiting myself or the scope of the invention, as many changes and modifications may be made without departing from the spirlt of a hydrocarbon backing form between the crown forms and uniting the crown forms and backing form by casting wax.

3. The method of forming a solid gold bridge which includes preparing crown forms for the adjacent teeth, securing a hydrocarbon backing form between the crown forms, inserting the bridge pattern in a mold, pouring in the molding material, heating the mold to volatilize the pattern, and pouring in molten metal.

THOMAS C. HANSEN. 

